The present invention relates generally to washing machines and, more particularly, to methods and apparatus for acoustically insulating a laundry tub thereof with an acoustical insulation blanket.
Washing machines have long been known as a convenient and efficient way to launder clothes following their use. In general, washing machines include a laundry tub for holding user-inserted clothes and washing soap and hot or cold water. During use, an agitator in the tub pivotally reciprocates thereby cleaning the clothes by mixing the water, soap and clothes together. Thereafter, clean water rinses the clothes and the tub spins to remove excess water. Unfortunately, this process generates considerable noise which can annoy users. In an effort to reduce this noise, those skilled in the art have covered the laundry tubs and/or other noise sources with acoustical insulation.
Conventional acoustical insulation for washing machines generally comprises sound transmission barriers and sound absorption layers. Typically, acoustical insulation involves enclosing the noise source in an insulation structure, such as a mineral fiber insulation, i.e., fiberglass, thereby attenuating the transmission of unwanted noise emanating from the washing machine.
The use of fiberglass, however, adversely causes skin irritability problems for handlers. Thus, more modem acoustical insulators have enclosed the fiberglass in polyethylene bags, for example. While generally successful at preventing skin irritations, the bags can be cumbersome and bulky thereby causing other handling issues. They also tend to prevent close tolerance fits between the tub and washing machine housing which can become a critical limitation since the laundry tub is required to spin many times during its lifetime.
Moreover, the bag has a tendency to xe2x80x9ccatchxe2x80x9d on other objects which further complicates packaging and handling. Of course, the bag may also catch during the routine spin cycles of the washing machine. Consequently, if it does catch, it will likely tear thereby exposing handlers and machine owners to the fiberglass. It may also create a sloppy appearance likely to detract from a customer""s satisfaction of the individual washing machine and/or company that manufactures/sells the machine.
In addition, manufacturers presently provide bag-wrapped-fiberglass with awkward straps, often metal, pierced through the bag to attach to mating clips on the laundry tub during installation. In turn, the straps add manufacturing steps and the metal may vibrate during spin cycles thereby increasing noise, not reducing it.
Accordingly, the washing machine arts desire improved acoustical insulation methods and apparatus for better meeting the needs of manufacturers, handlers and users.
In accordance with the purposes of the present invention as described herein, methods and apparatus are provided for acoustically insulating a laundry tub of a washing machine. The washing machine comprises a lid that provides user access to an interior of the laundry tub for depositing soiled laundry and washing soap. The laundry tub has a wall with one side disposed towards the interior and another side disposed towards an exterior. The exterior of the wall has at least one protuberance thereon. An acoustical blanket of thermoplastic material, with at least one hole therein, extends about and fits snugly against the exterior of the wall. The protuberance mates with and fills the hole of the acoustical blanket.
In other embodiments, the acoustical blanket has cutouts for providing access to the wall of the laundry tub and/or complimentary configured terminal ends. The laundry tub has single or multiple protuberances for mating with single or multiple holes of the acoustical blanket. The protuberances include vertically arranged protuberances, peripherally arranged protuberances or other. Preferred structures of protuberances include knobs or elongate members that may or may not mate with a recess of the wall.
In another embodiment, the acoustical blanket may mate directly with the washing machine instead of the laundry tub.
In accordance with yet another aspect of the present invention, a method is provided for providing a laundry tub with a protuberance on a wall thereof, enclosing the laundry tub with an acoustical blanket of thermoplastic material having a hole, and mating the protuberance with the hole. Crimping the acoustical blanket and providing wall access are also disclosed.
Still further, the acoustical blanket is formed from a polymer based thermoplastic material. That polymer based thermoplastic material is selected from a group consisting of a polyester, polyethylene, polyolefin, polypropylene, polyethylene terephthalate, rayon, nylon, acrylic, hemp, kenaf, cotton and combinations thereof.
The acoustical blanket may be composed of polyester staple fibers and polyester bicomponent fibers of distinct diameters typically between 8.0 and 50.0 microns and distinct lengths typically between 0.5 and 3.0 inches. It may also include melt blown microfibers.
In addition, the thermoplastic blanket may include a facing layer on the thermoplastic blanket. That facing layer may be selected from a group consisting of polyester, rayon, metallic foil and combinations thereof.
While the acoustical blanket derives its size from the size of the laundry tub, it may, in one embodiment, be described as comprising a layer of thermoplastic material having a length of about 50 inches, a height of about 17 to 20 inches, and a thickness of about xc2xe to 1xc2xd inches.
In the following description there is shown and described methods and apparatus for acoustically insulating a washing machine and, specifically, insulating a laundry tub thereof. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawing and descriptions will be regarded as illustrative in nature and not as restrictive.